Many Soviets died through out the war, yes I believe some 30 million total, which includes civilians as well as military members. Though, the US did give some supplies to the USSR, but when it came to defeating Hitler in the European Theater, then it was basically the USSR who took the fight to Hitler. The US won the Pacific Theater, while the USSR won the European one. Even after the USA invaded Normandy Hitler was already done for. The USSR was already pushing his ass back to Berlin, and out producing him like crazy. The Tiger/King Tiger were the only tanks that stood a chance against a T-34, but there were so many T-34's and just to few Tigers. If the USA did not invade, then the war would have just lasted longer, but Hitler was screwed either way.